1. Field of Invention:
This invention relates generally to a technique for manipulating the nominal notational values of a musical score with respect to the amplitude contour of individual tones, the relative loudness of different tones, slight changes in tone duration and other deviations from the nominal values which together constitute the expressive microstructure of music. More particularly, the invention deals with a computerized system capable of manual or automatic operation for impressing an expressive microstructure on a musical score inputted therein in terms of nominal notational values, the system being usable for composing music that includes microstructure.
Music has been defined as the art of incorporating intelligible combinations of tones into a composition having structure and continuity. A melody is constituted by a rhythmic succession of single tones organized as an aesthetic whole. The standard system of notation employs characters to indicate tone, the duration of a tone (whole, half, quarter, etc.) being represented by the shape of the character and the pitch of each tone by the position of the character on the staff. In such notation, a melody is a musical line as it appears on the staff when viewed horizontally.
While the notation of a musical score gives the nominal values of the tones, in order for a performer to breathe expressive life into the composition, he must read into the score many subtilties or nuances that are altogether lacking in standard notation. Some expressive subtilties are introduced as a matter of accepted convention, but most departures from the nominal values appearing in the score depend on the interpretive power of the performer.
Thus, a musical score, while it may indicate whether a section of the score is to be played loudly (forte) or softly (piano), does not generally specify the relative loudness of component tones either of a melody or of a chord with anything approaching the degree of discrimination required by the performer. The performer decides for himself how loudly specific notes are to be played to render the music expressive.
Even more important to an effective performance is the amplitude contour of each tone in the succession thereof. To satisfy musical requirements, the amplitudes of the tones must be individually shaped. Though, in general, amplitude contours are completely unspecified in standard notation, each performer, such as a singer or violinist, who has the freedom to shape tones, does so in actual performance to impart expressivity thereto. Indeed, with those instruments that lend themselves to tone shaping, variations in the amplitude shapes of the tones constitute a principal means of expression in the hands of an expert performer.
Another factor which comes into play in the microstructure of music are subtle deviations from the temporal values prescribed in the score. Thus, in actual performance, to avoid temporal rigidity which dehumanizes music, the performer will in actual practice amend the nominal duration values indicated by standard notation. These nominal values are arithmetic ratios of simple whole numbers such as 1/2, 1/3, 1/4, 1/16, etc.
Yet another expressive component of music which is unspecified in the score is the timbre to be imparted to each tone; that is, the harmonic content thereof. A performer of a string instrument, by varying the pressure and velocity of the bow on the string, can give rise, not only to variations in the loudness of the tone, but also variations in its tonal timbre independently of loudness. On a wind instrument, the performer can achieve similar effects by changes in lip pressure and wind velocity.
In short, the macrostructure of a musical composition is defined in the score by standard notation. If, therefore, one executes this score by being assiduously faithful to its macrostructure, the resultant performance, however expertly executed, will be bereft of vitality and expression. The term "microstructure" as used herein encompasses all subtle deviations from the nominal values of the macrostructure in terms of amplitude shaping, timing, timbre and all other factors which impart expressiveness to music.
It has been found that the measure of expressivity that can be attained using only sinusoidally-generated tones whose amplitude is shaped is quite surprising, despite the absence of harmonics which enrich the tones. Our ears appear to be highly sensitive to changing amplitudes and shapes, and our memories can effortlessly detect relative amplitudes and amplitude-shapes sounded in sequence in a musical context, even when the corresponding tones are sounded up to 10 or 15 seconds apart with many other tones in between.
This faculty of short term memory for comparing tone amplitudes and tone shapes makes it possible for the typical listener to distinguish between identical forms that are mostly perceived as mechanical and monotonous, and slightly varying forms; for the latter, played even a few seconds apart, are perceived in relationship to one another and can produce varied meaning and vitality. Thus, the relationships which constitute the microstructure in music, though not explicit in the score, are vital to its appreciation.
Essential also to an understanding of controllable microstructure in a system in accordance with the invention are A essentic forms; that is, the dynamic expressive forms of specific emotions; and B, the inner pulse of composers. These will now be separately considered.
As explained in an article by Clynes and Nattheim (pp47-82) included in Music, Mind and Brain: The Neuropsychology of Music, M. Clynes (ed.), Plenum Press, New York (1982), touch expressions of specific emotions such as love, grief and hate, can be transformed into sound expressions of like emotions; i.e., the nature of the transforms was found so that the sound expresses the same emotional quality as the touch expression from which it is transformed.
The touch expressions are measured by recording the transient forms of finger pressure when these are voluntarily expressed. The instrument enabling this measurement to be made is called the Sentograph; it measures both the vertical and horizontal components of finger pressure independently as vector components varying with time. The sentographic forms obtained are stored in a computer memory and can be reproduced at will. (See Clynes patent No. 3,755,922, "System for Producing Personalized Sentograms" which discloses in greater detail the nature of essentic forms and how sentographs are produced.)
In transforming the sentograms for touch expression of specific emotions into corresponding sound expressions it was found that the dynamic form (essentic form) of the touch was preserved to become the frequency contour of the sound. The sound is a frequency and amplitude modulated sinusoid. The amplitude modulation also was related to the dynamic touch form but needed to be passed through an imperfect differential network.
These expressive sound shapes of "continuous" frequency modulation are related to melodies which represent a form of "discrete" frequency modulation. As spelled out in the above-identified Clynes and Nattheim article, it is possible to create musical melodies which express an emotional quality similar to dynamic, expressive sound forms in such a way that the melodic steps of the created melody act to outline the frequency contour of the "continuous" form, and the amplitude contour of the expressive sound is preserved. As different melodic steps are chosen, the durations would be constrained so as to conform to the "continuous" frequency modulation wave. (essentic form).
The inner pulse of specific composers such as Beethoven, Mozart and Schubert, are expressed by sentographic forms obtained by having an individual think the music of a selected composer in his mind and by concurrently expressing the pulse by "conducting the music on a sentograph with finger pressure. The resultant sentograms indicate that major composers, such as those previously identified, impart individual pulse forms to their music which characterize their creativity identity or personal idiom. This inner pulse characteristic of each composer is, to a degree, analogous to individualistic brush strokes which distinguish one painter from another, regardless of the subject matter of their paintings. (See M. Clynes, "Sentics, The Touch of Emotions" - published by Doubleday - 1977.)